Method of selecting dyes for treating goods to alter the colors thereof



Patented July 3, 1934 UNITED STATES PATENT OFFICE THEREOF Lloyd '1. Howells, Cleveland, Ohio, assignor to The Electric Smelting & Aluminum Company,

Cleveland, Ohio No Drawing. Application January 2, 1932, Serial No. 584,579

9 Claims.

' or on white surfaces such as paper sheets.

In commercial laundries, for example, the bluing of washed goods is at the present time carried on without any means for measuring or determining either the particular shades of bluing necessary to produce white goods, or the strength or concentration of the bluing solution which is necessary to produce the desired results. In a great many cases, undesirable shades in the goods are intensified through the use of the wrong shade of dye. There are at present no means available to a laundryman to enable him to determine either the shade of the bluing that should be used, or the strength or concentration of the same, and consequently, through no fault of the laundryman, variations in the appearance of the washed goods occur when he uses bluing of slightly different shades.

It is well known that certain colors when mixed in proper proportions are complementary and produce white or black which, strictly speaking, are not colors, but white is the presence of all colors in proper proportions and black is the absence of all colors. Any tint commonly occurring in so-called white textile or other goods can be neutralized or modified to produce pure white, by adding a blend of the primary color which is complementary to the shade or tint of the goods. The ints encountered in laundered whitework range from yellow to red. To neutralizie or satisfactorily modify these tints it may be necessary to use a yellowish blue (green blue) or a reddish blue (violet) dye, depending upon the tint of the goods. This tint is generally common to all of the goods of the same nature which have been washed in a laundry by a certain washing process, or treated in a textile factory by some manufacturing or treating process, the tint depending upon the method of washing, the detergents and washroom supplies used, the nature of the water supply, and other causes. Consequently, different laundries or factories may require radically different shades of complementary dyes to offset or modify the undesirable tints in the laundry goods.

An object of the invention is to provide an improved method of selecting dyes for neutralizing or modifying colors on white surfaces such as textile goods, paper and the like; which will largely eliminate guesswork and enable more uniform and accurate results to be obtained; and

which may be practiced by'persons with a minimum of special training and requiring only simple equipment.

Other objects of this invention are to provide a method of determining the complementary color necessary to neutralize or modify any undesirable tint of textile materials or other, surfaces; also to provide a method of this kind, by means of which the intensity or concentration of the desired color can be determined; also to provide a simple and accurate method of blending dyes in solution to yield the exact complementary color blend required to neutralize or modify undesirable tints in fabrics; also to provide a method of dyeing so-called white textile or other materials, in accordance with which these materials will be of uniform whiteness in spite of variations in the shades of the dyes used; also to provide a process of dyeing textile materials or other goods, in accordance with which the user may prepare dye solutions of the desired character without testing, weighing, or matching the actual dye itself; also to improve methods of dyeing or bluing textile or other materials in other respects hereinafter specified.

In order to carry out my improved method, I employ fundamentally only two blue dyes of definite shade, one of the dyes being of a reddish blue or violet, and the other of a yellow or greenish blue. The two dyes selected must be compatible, that is, they must belong to the same classand have the same color index number or have noninterfering properties. In order to eliminate measuring of these dyes, I prefer to form the same into tablet form, by using an inert excipient, each tablet being of the same weight, so that all tablets contain exactly the same amount of a standard shade of dye. The tablets may, of course, be of any desired size. I

In order to determine exactly the shade and concentration necessary, I make up a number of dye solutions of an exact concentration, using in one of the solutions only one of the dyes, and in another solution only the other dye. I then make a number of additional solutions in which definite percentages of both the two dyes are used. There will then be available a number of dye solutions all of the same strength and each slightly different in shade from the others.

I then tint in these dye solutions pieces of transparent colorless sheet material, such for example as thin transparent colorless, solidified sheets of viscose, such as cellophane, which preferably, but not necessarily, is water absorbent. This tinting may be done by immersing a piece of this transparent material in each solution, so that there will be available a piece of this material tinted in accordance with each solution, and preferably the amount of this transparent material will be computed in proportion to the amount of dye in the sample. These differently tinted pieces are then placed over an unblued piece of fabric typical in color or shade of those treated in the laundry or factory, in such a manner that the fabric is seen through the tinted sheets of viscose material when exposed to sunlight or other source of white light. The most suitable complementary tint or tint that produces the desired appearance then immediately becomes very apparent to the naked eye, since it will be found that one of the pieces of dyed material completely neutralizes or modifies the undesirable tint and causes the portion of the article seen through this particular piece of tinted material to be of a much purer white or preferred tint than all other parts of the material, and some of the shades will actually increase or intensify the undesirable appearance of the portion of the article which they cover. Having selected the most suitable shade, the ratio of the two dyes employed in tinting the piece of transparent material producing the most perfect white or preferred tint is noted, and a blue or other dye solution is then made up in accordance with the percentages of the two dyes present in the solution with which this piece of viscose or other material was dyed.

It is not intended to restrict this invention to be used in connection with cellophane, since various other materials which are transparent and colorless and capable of being tinted by dyes, such as used in bluing processes, may be used. Solidified viscose, however, has been found to be admirably adapted for this purpose, since it takes from the dye solution a tint corresponding with that taken by the textile fabric, and may be prepared and used easily by the laundry manager and without special skill or equipment.

Instead of the viscose sheets, one may use other transparent bodies such as celluloid, paper,

. glass either in plates or spectacles, or transparent tubes containing a quantity of the test solutions. Also it is possible, but at present is less satisfactory, to prepare comparison devices by painting or spraying liquids of desired tints or colors on glass or other similar materials which are matched with the tints caused by the dyes. Also colored glasses or the like, in plates or spectacles, may be used if matched or compared with tints corresponding to tints produced by the dyes, so that they represent the effects produced by the dyes or combinations of them. If colored transparent plates or other bodies are used, one may also advantageously employ similar but uncolored plates or bodies for testing the neutralization necessary to offset the diminution of light in passing through that body. For example, when one desired to reproduce or match an exact tint or shade, in certain goods, one would examine the goods to be treated, through the assortment of prepared, standard, colored strips or sheets in turn, and select the one that gave most nearly the same appearance as the, goods having the shade to be matched had when viewed through similar, but uncolored, strips or sheets of the same materials, which would avoid any error in comparison caused by reflection or refraction of the light passing through the sheets or strips without the effect produced by the colors thereon or therein. This gives greater accuracy in the selection of dyes, blends of dyes, and concentrations which should be used.

It is also desirable to determine the strength or concentration of dye solutions desirable to produce the best effect. This can be accomplished by proceeding in a similar manner to make up dye solutions of varying concentrations and immersing small sheets of transparent colorless solidified viscose material in respective solutions, and then placing them over the textile as before described, to determine which sheet produces the best appearance.

By way of example, the two dyes can be made up in tablets of one-quarter ounce each, or in standard unit quantities of solutions that may be measured out by the user or marketed in capsules. Solutions are then made up, each containing one ounce of dye per gallon of water. One solution will contain say four tablets, capsules or measured units of the reddish blue dye, the next solution containing three tablets or units of the reddish blue dye, and one tablet of the yellowish blue dye, the third solution containing two tablets or units of the reddish blue and two of the yellowish blue dye, a fourth solution containing one tablet or unit of the reddish blue and three tablets of the yellowish blue dye, and the fifth solution containing four tablets or units of the yellowish blue dye, a gallon of water being used in each solution.

After complete dissolving of the tablets, solutions of each of the five solutions above referred to are volumetrically made up in concentrations of .00010%, .00015% and .00020% of dye per unit weight of water. This will produce for each of the original five solutions, three solutions each of different strength. A sheet of the colorless cellophane or other colorless transparent water absorbent material is then immersed in each of these solutions and dried. There will, therefore, be produced a series of standard sheets of the viscose material ranging from one to five in shade and from one to three in intensity of each shade. The dyed transparent sheets are then placed upon an undyed textile article and examined in a white light, whereupon the matching of both shade and intensity can be readily determined without the aid of any instruments. Upon selecting the specimen of cellophane producing the purest white or other desired appearance, the ratio and concentration to beused are, of course, determined to correspond with those used in dyeing this particular piece of transparent material or cellophane.

If desired, the tablets may be made of such size or concentration that any selected number of them will contain suiiicient dye for correctly tinting a specified amount of goods, within practical limits such as 100 pounds of washed clothes for example.

Knowing the correct ratio and intensity, the concentration of dye, weight of the goods to be blued or tinted, and the definite amount of water employed, the bluing or tinting operation is then under perfect control.

The method of selecting bluing herein described has the advantage that it can be employed in any laundry or other establishment operating on textile fabrics without special apparatus and without requiring a skilled chemist or physicist. The method described, while greatly facilitated by the use of dye in tablet form, may be carried out by use of dye in any form and has the advantage that it may be used whenever any change in the laundering or other process of treating the goods is made or whenever a new shipment of dye is received. It is well known that dyes including those used for bluing ordinarily vary considerably in shade unless very carefully selected by the dealer or purchaser. By the use of my process, a dye which is slightly off in shade can be corrected by adding dye of another shade as indicated by test with the tinted transparent sheets. Since these sheets are tinted with the same dye which is later used on the textile material, uniform whiteness or desired tinting of the textile material can be produced, even if the shade of dye varies from time to time.

I claim:

1. In a method of selecting dyes for treating goods to alter the color thereof, the step of predetermining the complementary color blend required to satisfactorily modify undesirable tints in goods, including forming a plurality of dye solutions varying in shade, tinting each of a series of colorless transparent members with a different one of said solutions, and examining a piece of said goods to be treated through said tinted members to determine which member and dye solution best modifies said undesirable tints.

2. In a method of selecting dyes for treating goods to alter the color thereof, the step of predetermining the complementary color blend required to satisfactorily modify undesirable tints in goods including forming a plurality of dye solutions varying in shade and concentration, tinting each of a series of colorless transparent members with a different one of said solutions, and examining a sample of said goods to be treated through said tinted members to determine which member best modifies said undesirable tints, and thereby indicate which dye solution to use in dying said goods to produce a desired appearance of the goods.

3. In a method of selecting dyes for treating goods to alter the color thereof, the step of examining a piece of said goods to be treated through each of a plurality of transparent members colored with different known shades and concentrations, each corresponding to a solution of a dye of standardized shade and concentration, to indicate the solution which should be used. to produce the desired color effect on said goods as observed through said members.

4. In the method of selecting dyes for dyeing goods to alter the color thereof, the steps which comprise forming solutions of dyes in a plurality of difierent shades and concentrations, tinting transparent sheets in said solutions, and then inspecting a specimen of untreated goods through said sheets to select the sheet which is most nearly complementary to the color of said goods.

5. In the method of selecting dyes for dyeing goods, the steps which include dyeing a number of specimen sheets of transparent colorless viscose material with dye solutions varying in shade and concentration, each sheet being treated with but one solution, and examining a specimen of said goods to be treated through said different dyed viscose sheets to determine which solution will best produce the desired shade in said goods.

6. In the method of selecting dyes for blueing white goods, the steps which include making solutions of dyes varying in shade and concentration by dissolving in water a number of standardized tablets of dyes of different shades, the percentages of the several dyes varying in different solutions, tinting sheets of transparent solidifled water absorbent viscose in said solutions, one sheet being tinted with only one solution, and inspecting a specimen of said goods unblued through said sheets to select the sheet which is most nearly complementary to the color of said goods.

7. In a method of selecting dyes for blueing white goods, the step of predetermining the shade and concentration of blue dye to be used, including making a plurality of water solutions containing known percentages of a plurality of blue dyes of different shades, tinting sheets of transparent, colorless, water absorbent material in said solutions, and inspecting a specimen of said goods unblued through said sheets to select the sheet which is most nearly complementary to the color of said goods, and thereby indicate which solution should be used to blue the goods and give them a white appearance.

8. In the method of selecting dyes for blueing white goods, the steps which include making solutions of dyes varying in shade and concentration by dissolving in separate and equal quantities of water standardized tablets of equal weight of dyes of different shades, the total number and selection of tablets in each solution being known, tinting colorless transparent sheets of absorbent material by immersing the same in said solutions, each sheet being immersed in but one solution, and inspecting a specimen of said goods, unblued through said sheets to select the sheet which is most nearly complementary to the color of said goods, which automatically indicates the shade and strength of the dye which when used as the bluing agent will give the whiteest appearance to said goods.

9. In a method of selecting dyes for treating goods to alter the color thereof and produce a color as nearly as possible identical with another sample of goods, which comprises examining the goods to be treated through each of a plurality of transparent members, colored with different known shades and concentrations, each corresponding to a solution of a dye or standardized shade and concentration, and also examining said sample through one of said members without color, whereby one may select the colored member which produces the color effect on said goods to be treated most nearly like the appearance of said sample viewed through said member without color.

LLOYD T. HOWELLS. 

